QrRapido/Controllers/TrackingController.cs

using Microsoft.AspNetCore.Mvc;
using QRRapidoApp.Services;
using System.Diagnostics;

namespace QRRapidoApp.Controllers
{
    /// <summary>
    /// Controller for tracking QR code scans (Premium feature)
    /// Handles redirect URLs and analytics
    /// </summary>
    [Route("t")]
    public class TrackingController : ControllerBase
    {
        private readonly IUserService _userService;
        private readonly ILogger<TrackingController> _logger;

        public TrackingController(IUserService userService, ILogger<TrackingController> logger)
        {
            _userService = userService;
            _logger = logger;
        }

        /// <summary>
        /// Track QR code scan and redirect to original URL
        /// URL format: https://qrrapido.site/t/{trackingId}
        /// </summary>
        [HttpGet("{trackingId}")]
        public async Task<IActionResult> TrackAndRedirect(string trackingId)
        {
            var stopwatch = Stopwatch.StartNew();

            using (_logger.BeginScope(new Dictionary<string, object>
            {
                ["TrackingId"] = trackingId,
                ["QRTracking"] = true
            }))
            {
                _logger.LogInformation("QR tracking request - TrackingId: {TrackingId}", trackingId);

                try
                {
                    // Get QR code from database
                    var qr = await _userService.GetQRByTrackingIdAsync(trackingId);

                    if (qr == null)
                    {
                        _logger.LogWarning("QR code not found for tracking - TrackingId: {TrackingId}", trackingId);
                        return NotFound("QR code not found");
                    }

                    // Increment scan count and update last access (fire and forget for performance)
                    _ = Task.Run(async () =>
                    {
                        try
                        {
                            await _userService.IncrementQRScanCountAsync(trackingId);
                            _logger.LogDebug("QR scan count incremented - TrackingId: {TrackingId}, NewCount: {NewCount}",
                                trackingId, qr.ScanCount + 1);
                        }
                        catch (Exception ex)
                        {
                            _logger.LogError(ex, "Error incrementing scan count - TrackingId: {TrackingId}", trackingId);
                        }
                    });

                    stopwatch.Stop();
                    _logger.LogInformation("QR redirect - TrackingId: {TrackingId}, Destination: {Destination}, ProcessingTime: {ProcessingTimeMs}ms",
                        trackingId, qr.Content, stopwatch.ElapsedMilliseconds);

                    // Redirect to original URL (HTTP 302 temporary redirect)
                    return Redirect(qr.Content);
                }
                catch (Exception ex)
                {
                    stopwatch.Stop();
                    _logger.LogError(ex, "QR tracking failed - TrackingId: {TrackingId}, ProcessingTime: {ProcessingTimeMs}ms",
                        trackingId, stopwatch.ElapsedMilliseconds);

                    // Return error page instead of exposing exception details
                    return StatusCode(500, "Error processing QR code");
                }
            }
        }

        /// <summary>
        /// Get analytics for a specific QR code (requires authentication)
        /// </summary>
        [HttpGet("analytics/{trackingId}")]
        public async Task<IActionResult> GetAnalytics(string trackingId)
        {
            var userId = User?.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value;

            if (string.IsNullOrEmpty(userId))
            {
                _logger.LogWarning("Analytics request without authentication - TrackingId: {TrackingId}", trackingId);
                return Unauthorized();
            }

            try
            {
                var qr = await _userService.GetQRByTrackingIdAsync(trackingId);

                if (qr == null)
                {
                    _logger.LogWarning("Analytics request for non-existent QR - TrackingId: {TrackingId}", trackingId);
                    return NotFound();
                }

                // Verify ownership
                if (qr.UserId != userId)
                {
                    _logger.LogWarning("Analytics request for QR owned by different user - TrackingId: {TrackingId}, RequestingUser: {UserId}, Owner: {OwnerId}",
                        trackingId, userId, qr.UserId);
                    return Forbid();
                }

                _logger.LogInformation("Analytics retrieved - TrackingId: {TrackingId}, UserId: {UserId}, ScanCount: {ScanCount}",
                    trackingId, userId, qr.ScanCount);

                return Ok(new
                {
                    trackingId = qr.TrackingId,
                    scanCount = qr.ScanCount,
                    createdAt = qr.CreatedAt,
                    lastAccessedAt = qr.LastAccessedAt,
                    content = qr.Content,
                    type = qr.Type
                });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error retrieving analytics - TrackingId: {TrackingId}, UserId: {UserId}",
                    trackingId, userId);
                return StatusCode(500);
            }
        }
    }
}